There is nothing more likely to raise the hackles of any self-respecting rationalist than to be confronted with the latest celebrity story about the miraculous healing power of homeopathy or some other “alternative” or “complementary” quackery. Or, embarrassingly, to discover that some of your best friends are also devotees.

This isn’t a new bugbear in response to some kind of New Age, middle-class hippiedom. Charles Darwin wrote in a letter to a cousin:

You speak about Homeopathy; which is a subject which makes me more wrath, even than does Clair-voyance: clairvoyance so transcends belief, that one’s ordinary faculties are put out of question, but in Homeopathy common sense and common observation come into play, & both these must go to the Dogs, if the infinetesimal doses have any effect whatever

There is no serious scientific debate about the efficacy of homeopathy. It performs no better than placebo and is based on principles wholly at odds with established scientific understanding. Nevertheless, it whips up what might seem like a disproportionate amount of political controversy.

A newly appointed public health shadow minister, Luciana Berger, was “forced to renounce” previously positive views.

And earlier in 2013, Chief Scientist Mark Walport called homeopathy “nonsense”, while his predecessor, John Beddington, said that NHS spending on homeopathy was the only issue where ministers had “fundamentally ignored” his scientific advice. Sally Davis, England’s Chief Medical Officer, said that the taxpayers’ £4m would be better spent on proven treatments as hospitals suffer painful cutbacks.

Our survey says

Yet while binary opposition between support for homeopathy (and other complementary and alternative (CAM) treatments) is how public debate is framed, it is far from clear that the public thinks and does the same.

In research we carried out using the Wellcome Monitor Survey, we interviewed a random sample of 1179 UK adults aged over 18 about homeopathy and other CAM. We also wanted to know why some people chose or not to use these treatments.

Hands up if you’ve tried it.Wellcome Monitor, 2009

A slim majority of the group reported that they had never used CAM. The most popular treatments with the remaining half were herbal medicines, homeopathy and acupuncture.

A quarter of the respondents who reported that they had never used homeopathy said this was because they hadn’t heard of it; a third because they had never been advised to take the treatment and/or that they’d never had an illness that required it; and 3% said it was because homeopathic remedies were too expensive.

Less than a quarter of non-users said that they had avoided homeopathy because they didn’t believe that it worked, or that conventional medicine worked better.

Of course, this may be in part a result of asking a question in a survey of this kind: it is quite hard for people to single out reasons for not doing things.

The most telling statistics emerged when we asked people that said they had used homeopathy why they had: 49% said they were “willing to try anything and didn’t think it could do any harm”. Only 16% said it was because they believed they worked better than conventional medicine. This means that only around 3% of the population have used homeopathy from a belief that it works where conventional medicine doesn’t. The rest either have not used it, or used it for other reasons.

Disaffected, conventional and dissonant

To explore this further, we used a statistical modelling technique called latent class analysis, which helps identify groups of persons that are similar to each other in their profile of survey responses. We selected questions for analysis based on the key dimensions of public debate: the importance of science education, belief in the effectiveness of homeopathy, use of CAM, trust in medical doctors and optimism about medical advances in general.

We found that we could split the public into three groups. The first, who we called the “disaffected”, comprise just under 30%. They are generally pessimistic about medicine, don’t see the value of science education and don’t believe in the efficacy of homeopathy either.

A second “conventional” group, accounting for just over 30% of citizens, are likely to be supportive and trusting of conventional medicine, reject CAM and value science education.

The third and largest group (just over 40% of the population) is the most interesting. This group is likely to have used CAM and to think that homeopathy is effective. Yet they are overwhelmingly trusting of medical doctors, value science education and are optimistic about medical advances. We call this group the “dissonants” (although they are unlikely to call themselves that).

So what makes it likely that someone will be a dissonant rather than a conventional? Women are more likely to be found in the dissonant group. Interestingly, people who are better educated are also more likely to be found in this group, (although from a set of questions we posed in the survey, those with a science qualification and who did better in a scientific quiz are less likely to be included), along with those that think that there’s too little regulation of medical research.

At odds in the public mind?

Our research suggests that nearly half of the public don’t believe and act as if CAM and conventional medicine are at odds. Coupled with the significant global industry that has grown up around CAM, it is easy to see why politicians have been unwilling to respond to the clear evidence that homeopathy and CAM are ineffective. In the US, it’s a $34bn industry where half of people report using them.

The competition between proponents and opponents of CAM in all likelihood is set to continue. But there’s some evidence that better science education can help people to distinguish between scientific and pseudo-scientific claims, and it appears that at least some of the openness to CAM might stem from concerns about how medical research is regulated. And it is these that might hold the key to who ultimately comes out of the ring in better shape.

The research on which this article is based was carried out with Paul Stoneman, Patrick Sturgis and Elissa Sibley.